Russia responded.

“Any aircraft, including planes and drones belonging to the international coalition operating west of the Euphrates river, will be tracked by Russian anti-aircraft forces in the sky and on the ground and treated as targets,” the Russian defence ministry said.

It denied the US had used a communications channel before the Su-22 fighter bomber was downed.

The memorandum of co-operation with the coalition aimed at preventing air incidents and guaranteeing flight safety was ending as of Monday, the defence ministry added.

It is not the first time communications have been suspended between the two sides – in April, the hotline was shut down after the US launched 59 Tomahawk cruise missiles at Syria’s Shayrat airbase in response to a suspected chemical weapons attack on a rebel-held town in Idlib province.